Ricardo Garilleti

Bryophyte spores are known for long-distance dispersal and tolerance to adverse conditions, but their comparative longevity remains poorly understood. In this work we assessed whether moss spores are as long-lived as spores and seeds of other land plants. Spores of Funaria hygrometrica, Lewinskya acuminata, L. iberica and Ulota crispula were subjected to accelerated aging (AA: 45 °C, 60% relative humidity [RH]) and dry storage (15% RH, 20 °C) with periodic germination tests. Different maturity stages of F. hygrometrica were also included. Estimated initial viability constant (Ki), standard deviation of spore deaths’ distribution in time (σ) and time for viability to drop to 50% (P₅₀) were determined by probit analysis from spore survival curves. Overall results showed short spore longevity for all species tested, regardless of storage conditions. P₅₀ ranged from 0.4 to 5.7 days (AA) and 58–150 days (dry storage), indicating faster deterioration than seeds or fern spores at the same storage conditions. In the case of F. hygrometrica, spores collected at peak maturity showed the longest longevity under both storage conditions. This study suggest that moss spores may be relatively short-lived, which could be related to their chlorophyllous nature. Ecological and conservation implications of this spore character are discussed.

In recent years, phylogenomic approaches have significantly deepened our understanding of moss diversity. These techniques have uncovered numerous previously overlooked species and provided greater clarity in resolving complex taxonomic relationships. In this context, the genus Rehubryum is particularly outstanding, because of its close morphological similarity to both Ulota and Atlantichella. The challenges posed by its segregation are addressed in this study, which integrates morphological and molecular data to reassess the circumscription of Rehubryum and its phylogenetic placement within the subtribe Lewinskyinae. Our results support the recognition of a new species, R. kiwi, and show that its inclusion within the genus further complicates the morphological delimitation of Rehubryum from Ulota, as both genera are distinguishable by only two consistent gametophytic characteristics: a submarginal leaf band of elongated cells, and the presence of geminate denticulations in the margins of the basal half of the leaf. Moreover, R. kiwi challenges the current morphological circumscription of Rehubryum itself, as it overlaps in key characteristics with its sister genus Atlantichella, rendering their morphological separation untenable. The striking interhemispheric disjunction between Rehubryum and Atlantichella raises new questions about long-distance dispersal and historical biogeography in mosses, despite these complexities at the generic level. Nevertheless, species-level distinctions remain well defined, especially in sporophytic traits and geographic distribution. These findings highlight the pervasive cryptic diversity within Orthotrichaceae, underscoring the need for integrative taxonomic frameworks that synthesize morphology, molecular phylogenetics, and biogeography to resolve evolutionary histories.

A new species of Orthotrichum was recently described based on a single collection from the Coquimbo Region of Chile and was then thought to be rare. However, new collections reveal this species as common in central and northern Chile, and since it was described on a single specimen, here we present amendments to the original description. Some of the inaccurately described morphological characters provided in the original description are of diagnostic importance for differentiating this endemic species within closest species of the genus. In addition, we provide data about the ecology of this taxon and an updated distribution map.

The bryophyte genus Ulota has its main diversification area in Patagonia, with 18 currently accepted species, all of which are endemic to the area. Despite this richness, ongoing studies indicate the existence of hitherto unknown species in this territory. However, the strong resemblance between species often complicates the discrimination of new taxa, making the use of integrative taxonomy approaches compulsory. During surveys conducted in past decades, a morphotype of a Ulota, closely resembling Ulota macrodontia, was discovered coexisting with this species. Ulota macrodontia is characterized by unique peristomial features within the genus, and the variant morphotype shares these characteristics while displaying some distinct gametophytic and sporophytic features. Biometric analyses demonstrate that the differences are stable, and without intermediate states. The results obtained from the analyses of one nuclear and four plastid loci reveal a close relationship between both morphotypes, with the samples of U. macrodontia forming a well-supported monophyletic group. We propose to treat the new morphotype at species level (Ulota brachypoda sp. nov.), discussing why this is the most appropriate taxonomic rank, and we provide a detailed and illustrated description. Additionally, a distribution map of the two endemics is included.

The morphological traits of the two known species of the genus Stoneobryum are reexamined based on newly collected materials. Observations on the Australian species, S. bunyaense, are derived from a recent collection made at the type locality, where it has been rediscovered. Those of S. mirum are based on recent field collections from numerous locations in eastern South Africa. Comprehensive descriptions of both species and illustrations of their key morphological characters are provided. The new data complement and correct previously available descriptions, especially the original one for the type species of the genus, S. bunyaense. Stoneobryum arises as a highly differentiated genus, well characterized by sporophytic and gametophytic characters. Its two species are very similar, but nevertheless certainly distinct; an identification key is provided.

Currently, a wide range of genomic techniques is available at a relatively affordable price. However, not all of them have been equally explored in bryophyte systematics. In the present study, we apply next‐generation sequencing to identify samples that cannot be assigned to a taxon by morphological analysis or by Sanger sequencing methods. These samples correspond to a moss with an enigmatic morphology that has been found throughout Western Europe over the last two decades. They exhibit several anomalies in the gametophyte and, on the rare occasions that they appear, also in the sporophyte. The most significant alterations are related to the shape of the leaves. Morphologically, all specimens correspond to mosses of the genus Lewinskya, and the least modified samples are potentially attributable to the Lewinskya affinis complex. Specimen identifications were first attempted using up to seven molecular markers with no satisfactory results. Thus, we employed data generated from targeted enrichment using the GoFlag 408 flagellate land plant probe set to elucidate their identity. Our results demonstrate that all the enigmatic samples correspond to a single species, L. affinis s.str. This approach provided the necessary resolution to confidently identify these challenging samples and may be a powerful tool for similar cases, especially in bryophytes.

Premise: Bryophytes form a major component of terrestrial plant biomass, structuring ecological communities in all biomes. Our understanding of the evolutionary history of hornworts, liverworts, and mosses has been significantly reshaped by inferences from molecular data, which have highlighted extensive homoplasy in various traits and repeated bursts of diversification. However, the timing of key events in the phylogeny, patterns, and processes of diversification across bryophytes remain unclear.Methods: Using the GoFlag probe set, we sequenced 405 exons representing 228 nuclear genes for 531 species from 52 of the 54 orders of bryophytes. We inferred the species phylogeny from gene tree analyses using concatenated and coalescence approaches, assessed gene conflict, and estimated the timing of divergences based on 29 fossil calibrations.Results: The phylogeny resolves many relationships across the bryophytes, enabling us to resurrect five liverwort orders and recognize three more and propose 10 new orders of mosses. Most orders originated in the Jurassic and diversified in the Cretaceous or later. The phylogenomic data also highlight topological conflict in parts of the tree, suggesting complex processes of diversification that cannot be adequately captured in a single gene‐tree topology.Conclusions: We sampled hundreds of loci across a broad phylogenetic spectrum spanning at least 450 Ma of evolution; these data resolved many of the critical nodes of the diversification of bryophytes. The data also highlight the need to explore the mechanisms underlying the phylogenetic ambiguity at specific nodes. The phylogenomic data provide an expandable framework toward reconstructing a comprehensive phylogeny of this important group of plants.